Bathtub rebuild drain issues!!

[deprived]

Okay. I messed up - I admit that.

I tore out the old shower in our 2008 Tiffin and replaced it with a bathtub. It was a huge effort that took several weeks to complete.

And now for the bad news.

The new tub fills up with drain water from the bathroom sink because the new tub sits about three inches lower than the old shower. That little bit of difference is just enough to allow the sink to drain partially into the tub which fills up with about one or two inches of water.

I have two choices to fix this, as far as I can see.

1: rip out the new tub and rebuild the entire thing. Let’s call that plan “B”. Or plan “Z”. I really, really don't want to do that.

2: make the tub drain pipe a bit lower and plumb a new second line to the grey tank. This new line from the tun drain will drop down a few inches beneath the floor and enter the grey tank from the side rather than the top. This will diminish my grey tank capacity a bit but it’s still a hell of a lot easier and cheaper than undoing a month’s worth of work.



There are some issues with cutting a new fitting into the grey tank but I’ve see a few methods using ABS fittings and solvent-cements that seem to work well. That part is tricky but surmountable. Otherwise it is a fairly straightforward job.


I’m not saying this is a perfect plan (or even a good one) but I wanted to put it out there to see what you all might have to say in terms of other ideas or improvements to the plan.

I found a picture of the old drain, and I can see that it sits about three inches higher than my new configuration.


NOTE: my diagrams are not all that accurate but I think they illustrate my situation.

[Lantley]

Halmfamily wrote:
Can't you just leave the tub drain closed when not using it. The water can't back up into the tub then unless your overflow drain is also an issue.

That would work until he went to use the tub. Once he opened the tu drain the grey water would rush/flow in.
You could consider a check valve in the drain line.

[Halmfamily]

Can't you just leave the tub drain closed when not using it. The water can't back up into the tub then unless your overflow drain is also an issue.

[MrWizard]

where do you camp, how do you drive
always somewhere with hookups, always dump before you move ?

i think i would remove the tub and raise it, aka do it right

you run the risk with your fix, of getting more than just the basin water
backing up in your tub
near full hard corners, could get some really bad grey water in the tub
sure the 'water might drain' on the next opposite turn
but kind of scum would it leave behind in the tub ?